What is the 'Columbus strain'? New Covid-19 variant discovered in Ohio likely more infectious, says study
A research team has discovered two new variants of the coronavirus, and they may have originated in the US. One of the strains prevalent in Columbus, Ohio, appears to spread more easily, say researchers from The Ohio State University Wexner Medical Center and College of Medicine. Dubbed as the “Columbus strain,” this variant has acquired three other gene mutations not previously seen together in SARS-CoV2, the virus that causes Covid-19, report authors.
The scientists note that the discovery of the Columbus variant, COH.20G/501Y, suggests that the same mutation may be occurring independently in multiple parts of the world during the past few months. The findings are under review for publication and appear in BioRxiv as a pre-print. The US Centers for Disease Control and Preventionis (CDC) is currently reviewing the new study.
“This new ‘Columbus strain’ has the same genetic backbone as earlier cases we’ve studied, but these three mutations represent a significant evolution. We know this shift didn’t come from the UK or South African branches of the virus,” said study leader Dr Dan Jones, vice-chair of the division of molecular pathology.
What do investigators know so far?
The Ohio State Wexner Medical Center has been sequencing the genome of SARS-Cov-2 viruses in patients with coronavirus since March 2020 to monitor the evolution of the virus.
The second variant carries a mutation identical to the strain found in the UK, but it likely arose in a virus strain already present in the US. This variant was discovered in one patient from Ohio, so researchers do not yet know the prevalence of the strain in the population. In contrast, the evolving strain with the three new mutations has become the dominant virus in Columbus during three weeks in late December 2020 and January 2021.
Like the UK strain, both newly detected mutations affect the spikes that stud the surface of SARS-Cov-2. The spikes enable the virus to attach to and enter human cells. Like the UK variant, the mutations in the Columbus strain are likely to make the virus more infectious, making it easier for the virus to pass from person to person.
“The big question is whether these mutations will render vaccines and current therapeutic approaches less effective. At this point, we have no data to believe that these mutations will have any impact on the effectiveness of vaccines now in use. It’s important that we don’t overreact to this new variant until we obtain additional data,” advises Peter Mohler, a co-author of the study and chief scientific officer at the Ohio State Wexner Medical Center and vice dean for research at the College of Medicine.
According to Mohler, it is important to understand the impact of mutations on the transmission of the virus, the prevalence of the strain in the population, and whether it has a more significant impact on human health. “Further, it is critical that we continue to monitor the evolution of the virus so we can understand the impact of the mutant forms on the design of both diagnostics and therapeutics. It is critical that we make decisions based on the best science,” he adds.
New Covid-19 variants
Viruses constantly change through mutation, and new variants of a virus are expected to occur over time. Several Covid-19 variants are circulating globally. Earlier this month, the White House coronavirus task force had warned states earlier this month that there may be a US variant that is “already spreading in our communities and maybe 50% more transmissible.” The CDC, however, said that it had not seen the emergence of a new US variant of the coronavirus.
In the UK, a new variant has emerged with an unusually large number of mutations. This variant seems to spread more easily and quickly than other variants. Currently, there is no evidence that it causes more severe illness or increased risk of death, or that it has any impact on vaccine efficacy. The CDC is tracking cases of the UK variant. The agency has identified 76 coronavirus cases with the B.1.1.7 mutation in the US.
In South Africa, another coronavirus variant has emerged independently of the variant detected in the UK. This variant, originally detected in early October, shares some mutations with the variant detected in the UK. There have been cases caused by this variant outside of South Africa. This variant seems to spread more easily and quickly than other variants. Currently, there is no evidence to suggest that this variant has any impact on disease severity or vaccine efficacy.
Another variant recently emerged in Nigeria. The CDC is also monitoring this strain but at present, there is no evidence to indicate this variant is causing more severe illness or increased spread of Covid-19 in Nigeria.